/**
 * C Implementation: grib_set_keys
 *
 * Description: how to set key values in GRIB messages
 *
 */
#include <stdio.h>
#include <stdlib.h>

#include "eccodes.h"

int sfx_grib_set_keys()
{
    int err = 0;

    const char *infile = "d:/sfxData/ecmwf/eccodes_test_data/regular_latlon_surface.grib1";
    const char *outfile = "d:/temp/out.grib1";

    FILE *in = fopen(infile, "rb");
    if (!in)
    {
        fprintf(stderr, "Error: unable to open file %s\n", infile);
        return 1;
    }

    FILE *out = fopen(outfile, "wb");
    if (!out)
    {
        fprintf(stderr, "Error: unable to open file %s\n", outfile);
        fclose(in);
        return 1;
    }

    // create a new handle from a message in a file
    codes_handle *h = codes_handle_new_from_file(0, in, PRODUCT_GRIB, &err);
    if (h == NULL)
    {
        fprintf(stderr, "Error: unable to create handle from file %s\n", infile);
    }

    // set centre as a long
    long centre = 80;
    CODES_CHECK(codes_set_long(h, "centre", centre), 0);

    // set paramId and shortName - normally you would do one or the other
    CODES_CHECK(codes_set_long(h, "paramId", 500004), 0);

    // the value of str_len is not used, it can be anything!
    size_t str_len = 0;
    CODES_CHECK(codes_set_string(h, "shortName", "fis", &str_len), 0);

    // get centre as a long
    long long_value = 0;
    CODES_CHECK(codes_get_long(h, "centre", &long_value), 0);
    printf("centre long value=%ld\n", long_value);

    // get centre as a string - cnmc = 80
    char string_value[100];
    size_t len = sizeof(string_value) / sizeof(char);
    CODES_CHECK(codes_get_string(h, "centre", string_value, &len), 0);
    printf("centre string value = %s\n", string_value);

    // get the coded message in a buffer
    size_t size = 0;
    const void *buffer = NULL;
    CODES_CHECK(codes_get_message(h, &buffer, &size), 0);

    // write the buffer in a file
    if (fwrite(buffer, 1, size, out) != size) {
        perror(outfile);
        exit(1);
    }

    codes_handle_delete(h);
    fclose(out);
    fclose(in);
    return 0;
}
